Re: [Gumstix-users] Vbat power on overo ?

The Tobi schematics are here:
http://pubs.gumstix.com/boards/TOBI/
The DC-DC chip specs should be available from somewhere to show the
maximum input voltage and whether or not the polarity is important.
My guess would be that you couldn't safely reverse the polarity.
On 1/10/10, alxx <alxx@...> wrote:
>> There is no DC socket on the Overo. Perhaps you mean one of the
>> expansion boards? The expansion boards have a DC-DC converter that
>> steps down the voltage from the DC jack to 3.3V to power the Overo.
>>
>
>
> Sorry using tobi expansion boards.
>
> Just trying to work out rest of the power options.
>
> What is the maximum safe input to tobi on the dc socket ?
>
> Be nice , if all I had to do was polarity protection and
> low voltage cutoff.
>
> Do the VBat connections have any sort of polarity protection ?
>
> Thank you
>
> Alex
>
>
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Thread view

Is there any information on voltage levels for the vbat connections on
overo ?
max , min and max current ?
Couldn't spot anything for overo on the wiki.
I'm powering from 6V sla batteries (may also have to power from 12/24v
systems, find out in next few weeks)
but may have to switch to 12V .
Need to get 5 -6 days of run time
One set of boards is using overo + tobi + (1-2)external wifi + 2x
bluetooth + 3G modem(dodo(optus))
and powered via usb hub
Other is overo air + tobi + 3G modem
Using panasonic MN1380 chips for low voltage cutoff .
(solarbotics sell small quantities)
http://www.edn.com/archives/1998/091198/pdfs/17d22531.pdf
Using the U version with 4.6- 4.9 cutoff .
Just working out rest of regulation circuit , once I have the current
draw figures (sometime this afternoon).
Thanks
Alex Gibson
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You can see the voltage requirements from the PMIC document.
http://focus.ti.com/docs/prod/folders/print/tps65950.html
In short, between about 3.1V and 4.6V seems to work fine with my Earth
boards. Less than 3.1V and the board resets. Above 4.6V and the PMIC
is not designed to cope.
On 1/5/10, Alex Gibson <alxx@...> wrote:
>
> Is there any information on voltage levels for the vbat connections on
> overo ?
> max , min and max current ?
>
> Couldn't spot anything for overo on the wiki.
>
> I'm powering from 6V sla batteries (may also have to power from 12/24v
> systems, find out in next few weeks)
> but may have to switch to 12V .
> Need to get 5 -6 days of run time
>
> One set of boards is using overo + tobi + (1-2)external wifi + 2x
> bluetooth + 3G modem(dodo(optus))
> and powered via usb hub
>
> Other is overo air + tobi + 3G modem
>
> Using panasonic MN1380 chips for low voltage cutoff .
> (solarbotics sell small quantities)
> http://www.edn.com/archives/1998/091198/pdfs/17d22531.pdf
> Using the U version with 4.6- 4.9 cutoff .
>
> Just working out rest of regulation circuit , once I have the current
> draw figures (sometime this afternoon).
>
>
> Thanks
>
> Alex Gibson
>
>
>
> --
> UTS CRICOS Provider Code: 00099F
> DISCLAIMER: This email message and any accompanying attachments may contain
> confidential information. If you are not the intended recipient, do not
> read, use, disseminate, distribute or copy this message or attachments. If
> you have received this message in error, please notify the sender
> immediately and delete this message. Any views expressed in this message
> are those of the individual sender, except where the sender expressly, and
> with authority, states them to be the views the University of Technology,
> Sydney. Before opening any attachments, please check them for viruses and
> defects.
>
> ------------------------------------------------------------------------------
> This SF.Net email is sponsored by the Verizon Developer Community
> Take advantage of Verizon's best-in-class app development support
> A streamlined, 14 day to market process makes app distribution fast and easy
> Join now and get one step closer to millions of Verizon customers
> http://p.sf.net/sfu/verizon-dev2dev
> _______________________________________________
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> gumstix-users@...
> https://lists.sourceforge.net/lists/listinfo/gumstix-users
>

> You can see the voltage requirements from the PMIC document.
>
> http://focus.ti.com/docs/prod/folders/print/tps65950.html
>
> In short, between about 3.1V and 4.6V seems to work fine with my Earth
> boards. Less than 3.1V and the board resets. Above 4.6V and the PMIC
> is not designed to cope.
So Vbat goes straight to the PMIC ?
What about the dc socket in ?
Doesn't that get dropped from 5V to 4V ?
Thanks
Alex

There is no DC socket on the Overo. Perhaps you mean one of the
expansion boards? The expansion boards have a DC-DC converter that
steps down the voltage from the DC jack to 3.3V to power the Overo.
On 1/10/10, alxx <alxx@...> wrote:
>> You can see the voltage requirements from the PMIC document.
>>
>> http://focus.ti.com/docs/prod/folders/print/tps65950.html
>>
>> In short, between about 3.1V and 4.6V seems to work fine with my Earth
>> boards. Less than 3.1V and the board resets. Above 4.6V and the PMIC
>> is not designed to cope.
>
> So Vbat goes straight to the PMIC ?
>
> What about the dc socket in ?
> Doesn't that get dropped from 5V to 4V ?
>
>
> Thanks
>
> Alex
>
>
> ------------------------------------------------------------------------------
> This SF.Net email is sponsored by the Verizon Developer Community
> Take advantage of Verizon's best-in-class app development support
> A streamlined, 14 day to market process makes app distribution fast and easy
> Join now and get one step closer to millions of Verizon customers
> http://p.sf.net/sfu/verizon-dev2dev
> _______________________________________________
> gumstix-users mailing list
> gumstix-users@...
> https://lists.sourceforge.net/lists/listinfo/gumstix-users
>

> There is no DC socket on the Overo. Perhaps you mean one of the
> expansion boards? The expansion boards have a DC-DC converter that
> steps down the voltage from the DC jack to 3.3V to power the Overo.
>
Sorry using tobi expansion boards.
Just trying to work out rest of the power options.
What is the maximum safe input to tobi on the dc socket ?
Be nice , if all I had to do was polarity protection and
low voltage cutoff.
Do the VBat connections have any sort of polarity protection ?
Thank you
Alex

The Tobi schematics are here:
http://pubs.gumstix.com/boards/TOBI/
The DC-DC chip specs should be available from somewhere to show the
maximum input voltage and whether or not the polarity is important.
My guess would be that you couldn't safely reverse the polarity.
On 1/10/10, alxx <alxx@...> wrote:
>> There is no DC socket on the Overo. Perhaps you mean one of the
>> expansion boards? The expansion boards have a DC-DC converter that
>> steps down the voltage from the DC jack to 3.3V to power the Overo.
>>
>
>
> Sorry using tobi expansion boards.
>
> Just trying to work out rest of the power options.
>
> What is the maximum safe input to tobi on the dc socket ?
>
> Be nice , if all I had to do was polarity protection and
> low voltage cutoff.
>
> Do the VBat connections have any sort of polarity protection ?
>
> Thank you
>
> Alex
>
>
> ------------------------------------------------------------------------------
> This SF.Net email is sponsored by the Verizon Developer Community
> Take advantage of Verizon's best-in-class app development support
> A streamlined, 14 day to market process makes app distribution fast and easy
> Join now and get one step closer to millions of Verizon customers
> http://p.sf.net/sfu/verizon-dev2dev
> _______________________________________________
> gumstix-users mailing list
> gumstix-users@...
> https://lists.sourceforge.net/lists/listinfo/gumstix-users
>

On 10/01/2010 7:06 PM, R. P. McMurphy wrote:
> The Tobi schematics are here:
>
> http://pubs.gumstix.com/boards/TOBI/
>
> The DC-DC chip specs should be available from somewhere to show the
> maximum input voltage and whether or not the polarity is important.
>
> My guess would be that you couldn't safely reverse the polarity.
>
Thank you I didn't realise the tobi schematics were available.
Going with just the low voltage cutoff circuit and a doide for polarity
protection.
Thank you
Alex
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Sydney. Before opening any attachments, please check them for viruses and
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